Any biography of Vesuvius is bound to be an open-ended affair. The story of this shifting, threatening mountain, rising so blithe and sublime above the Bay of Naples, is a long one of which we know very little. The earliest descriptive evidence is frustratingly epigrammatic, depending on the scant remarks of classical poets, historians and geographers and only amplified with Pliny the Younger’s two famous letters, looking back in memory but with crystalline clarity on the events of AD 79 after a thirty-year interval.